This instructable was created in fulfillment of the project requirement of the Makecourse at the University of South Florida (www.makecourse.com).
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Step 1: Tools/Materials Needed
(2) Nine gram servo motors
(1) 3-D Printer
(1) 2x3 Polycarbonate sheet
(1) IR sensor/remote
(1) 9 Volt battery
(10-15) 6-32 x 1/2" PPHMS
(10-15) 6-32 nuts
(1) 3" Clear Corner Guard
(1) Electric Drill
Varies drill bits.
Bag of zip ties
Step 2: Get an Idea How You Want the Mailbox
Having a AutoCAD software will be very beneficial at this time. Most traditional mailboxes look the same so above is the CAD drawing of my mailbox.
Step 3: Manufacture the First Prototype
Having a 3-D printer allows the transition from the CAD drawing to your first prototype very easy. Luckily, I had a big enough printer that I was able to print the actual size of my mailbox that I originally design with my CAD software.
WARNING! Do not leave your 3-D printed parts in a hot car in Florida, they will deform and mess up you print.
On that note, I decided to use the parts that was not damaged from the heat, which was the flag and the door and manufacture the rest of the mailbox from polycarbonate.
Step 4: Manufacturing Polycarbonate Mailbox
If you are manufacturing the mailbox from polycarbonate, measure and make the dimensions of your mailbox. Then make the appropriate cuts, I had a circular saw, so I was able to use that.
Even out the sides of the cutout polycarbonate, I used a milling machine.
A grinding belt was used to fillet a couple of the corners.
Step 5: Building the Mailbox
Cut the Corner Guard to appropriate sizes and build the rectangular mailbox using the corner guards as supports.
Measure and mark where the shaft of the flag and door will be, and with the electric drill and corresponding drill bits, drill three holes. One for the shaft of the flag and two for the shaft of the door.
At this point, we should have a decent setup of the mail box. We should now start 3-D printing a few more parts to make sure everything will work as planned. We can start with shafts, collar shafts and supports for the motors to rest on.
Lets not forget the beauty of 3-D printing, we can literally make/modify anything that comes to mind.
Step 6: Reinforcing the Mailbox
Use the PPHMS and the nuts to reinforce the corner guides.
Use the PPHMS and the nuts to hold the motor supports stable.
Once you have a good idea how the setup is going to be start supergluing the collar shafts to the door of the mailbox so when the shaft rotates, the door moves as well. Also superglue the flag to its shaft so when the motor rotates, the flag does as well.
The superglue is used to guarantee the door and flag moves when it is needed and stationary when it isn't needed. Be sure before using the superglue that the shaft and the hole is already a snug fit.
Step 8: Programming the Mailbox
Using the Arduino program the IR sensor to read from the remote and give a signal to move each servo when a single button is pressed.
The block diagram, Arduino setup, and code is above.
Step 9: Extra Improvements
Washers may be need to guarantee the flag does not hit the side of the mailbox when moving.
Be sure to have good wire management. When it comes to the mailbox there isn't a lot of space to hide the wires, so we could at least make sure they are as neat as possible.
It would also be beneficial to make a designated spot for the Arduino in the back of the mailbox.